Signaling apparatus and circuits



J. F. TOOMEY SIGNALING APPARATUS AND CIRCUITS.

APPLICATION FILED APR. 24. I919- &4i31,995, Patented Oct. 17, 1922.

INVEN TOR.

ATTORNE Patented @et. 17, 1922.

STATES rare threat JOHN F. TOOMEY, or NEW YORK, N. }Y., AssIGNo ro AMERICAN TELEPHONE AND TELEGRAPH COMPANY, A conronarron or NEW YORK.

" SIGNALING APPARATUS AND cmourrs.

Application filed April 24, 1919. Serial No. 292,333.

To all whom it may concern. 1

Be it known that I, JOHN F. TOOMEY, residing at New York, in the county of New York and State of New York, have invented certain Improvements in Signaling Apparatus andCircuits, of which the following is a specification.

This invention relates to signaling apparatus and circuits, more particularly it relates to apparatus and circuits for selectively signaling over telephone lines.-

In modern long distance telephone practice the central offices are generally so arranged that certain operators, known as the inward operators, handle all the calls coming into the oflice, while certainotheroperators, generally called the outward operators,-attend to the calls for distance oflices. 1 The signal circuits of the telephone lines are so arranged that the inward operators receive all the signals from the distant oflices. When, therefore, an operator at a distant ofiice desires to communicate with the out- 1 ward operator, she mustfirst call the inward This invention, in a broad aspect, efl'ects selection between the different operators positions by use of signaling currents differing in certain characteristics, together with apparatus selectively responsive to currents of such characteristics. V In the preferred form of the invention the characteristic difference between the signaling currents resides in the frequencies thereof. Jacks and associated apparatus are provided whereby different frequencies of signaling current may be sent over the line according to the jack usedby the operator; frequency responsive apparatus associated with the line causesthe signal to appear at that position only, whichis being called.

This invention further provides apparatus which, when theline is in use from one ofice to an office intermediate its terminals, applies a tone current to the .nonused portion of the line to indicate that. the other part thereof is busy. This tone current may be codified to indicate which intermediate station is usingthe line,in case more than one such station is associated therewith.

The above and variousother features and objects of this invention will be readily understood from the following description when considered in connection with the accompanying drawing showing a diagrammatic view of one form and arrangement of apparatus embodying this invention.

In this drawing reference characters I A and C designatethe terminal offices of a long distance line L. The apparatus at oilice C is similar to that at office A, and has been omitted from the drawing in order to prevent unnecessary crowding. Intermediate to ofiices A and C is an oflice B, the apparatus of which will be described hereinafter.

At station A are answering lamps 4 and 5,. the former being one of the inward answering lamps for calling an inward operator, and the latter being one of the outward answering lamps for signaling to an outward operator. Apparatus is provided at oflice A whereby lamps 4 and 5 are caused to'respond "to signaling current coming in on line L, which apparatus comprises a transformer 30, the primary of which is connected across'the line, and the secondary of which is associated with the grid circuit ofa vacuum tube amplifier 31, in accordance with the invention shown and described in the patent of S. P. Shackleton, N 0. 1,411,385, issued April 4, 1922, for signaling apparatus. The amplified signaling current flows through relays 22 and 23 connected in parallel in the output circuit of tube 31. These relays are of the frequency responsive type,

relay 22 being responsive onlyto 60 cycle 27. Relay 19 it thus de-energized and operates its contactto close the circuit of a lamp relay 18, which circuit extends from a battery 32 through the back contact of a cut-off relay 17, lamp relay 18, back contact 33- of relay 21' and the contact of relay 19 to ground. Relay 18 is thus energized and closes its front contact .35- which connects 4 so that this lamp gives the signal to the inward operator.

Belay 19-isre-energized as soonas the 60,

cycle signaling current ceases to come in over the line; and .in order to prevent the signal; from disappearing at lamp 4: until answered bythe operator, relay 18 is-provide'd witha holding circuit extending from battery 32 through its own contact 34 to ground. This circuit holds relay 18 energized' and thus causes, lainp 4: to remain liteven after relay 19 has returned to its normal condition. y j

When the operator resoonds to lamp 4 by inserting the plug36 0 her cord into one of the j acks, say 2, the cord battery 37 sends cirrrentthrough the sleeve resistanceilt and cutoif relay 17, so that this relay opens its back contact and disconnects battery 32 from lamp 1, and also from'lamp relay 18. Larnpll; is thus extinguished and relay 18 restored to its unenergized condition. y

In case the distant operator for any reason now desires to signal again to the inwar'd operatofis position at stationA, she

will not be able to cause a renewed response of relay 18 and lamp 1 because both of these are disconnected from battery 32 I: the cutoff relay 17. However, the relay 21 is now connected with battery 32 by relay Relay 21 therefore holds its front contacts closed and thus connects at front contact33 the circuit of a relay 6 with the back contact of relay 19. Consequently, when'relay 19 connects ground to its back contact inresponse to a renewed 6O cycle ringingcurrent, relay 6 is energized and connects a sourceof 16 cycle ringing current tofthe tip and ring of the answering jack, so thatthis current flows through the toll cord circuit and causesthe toll cord supervisory signal .79 to respond. The inward operator is thus notified that the distant operator is again signaling to her.

The circuits and apparatus for the con-' trol of lamp 0 are similar to those of lamp 4, and need notbe separately described. It issuflicient to point out that the relay 23 responsive to the 135 cycle, current controls a slow release relay 20, which in turn cona 1- i l trols a lamp relay 161101 governing lamp 0. j The apparatus of'th1sinVent1on thus selectively responds to 60. and 135 cycle cur rent, so that one or the other position at a terminal oflice may be called according to the frequency of current sent over. the line.

135 cycle current. A relay 10 normally connectsthe 6O cycle source to the front contacts 410 and 41 of relay 11 and when operated by current from battery it connects the 135 cycle source to these contacts. Front contacts 40and 411 are normally open but are connected with the line L when relay 11 is energized. H a

To signal to the inward operators position at office C, the operator inserts the plug of her toll cord into jack 2 and operates her ringing key 55 in the usual manner, so that 16 cycle ringing current is applied to the ti and ring of the jack and flows over the line conductors through transformer 30 and marginal relay7. This relay being selectively responsive to 16 cycle current, operates its contact and thus closes the circuit of relay 11, which circuit extends from battery 71, through the winding of relay 11, through the contact of relay 7 and contact 57' of a relay 13 to, ground. I Relay 11 closes contactsdtl and 41. and thus applies 6O cycle ringing current to line L, which current flows over the line to the office C and there causes response. of the inward answering ama a To signal to the outward operators position at office C, theoperator at A inserts plug 36 into jack 3 and manipulates her ringing key. As soon as the plug is inserted into the jack battery .37 causes the op" eration of the sleeve relay 15 connected in'series with the cut-off relay 17, and the sleeve relay causes the energization of the relay 10 so that this relay applies 135-cycle current to front contacts 4E0 and 11. lVhen, therefore, the operator manipulates the ringing key 55 and thus causes the operation of relay 11, current of a frequency'of 135 cycle is, sent out over the line to cause the response of. the outward answering lamp at the office C. Y

Oflice A is further equipped with a jack 1 for signaling tothe operators position at theintermediateoffice B, this position being equipped with a signal device responsive only to 16 cycle current as will be described hereinafter. lVhen the operator at office A inserts the plug of her cord into jack 1, the

sleeve battery/of the cord energizes the sleeve.

ringing key 55 and impresses '16 cycle current on the line conductors,'relay 11 fails to respond'to relay 7, so that the 16 cycle ring ing current flows through the back contacts of relay 11, over the line L to the intermediate station, where it causes response of the signaling apparatus as described below. It should here be noted that the 16 cycle current thus sent out from office A also reaches office where it flows through thewinding of a inai'giiialrelay corresponding to the relay 7 at ofiice A. This relay is so adjusted, however, that it fails to respond to the current from ofliceA, and this current consequently has no effect at oiiiceC. An operator at otfice A is thus enabled to call any one of the other operators positions associated with the line by merely plugging into the jack corresponding to the position she desires to call, and operatingthe ringing key.

T he signaling apparatus above referred to for calling an operator at the intermediate oiiice B may be an annunciator 42, connected across the line conductors together with a condenser 43 and an inductance 44, so pr0- portioned that the annunciator respondsto l6 cycle current but not to current of the other signaling frequencies, i. e. 60 and 135 cycles. Any other suitable frequency responsive device may be used, however, when desired. A ack 45 is provided, whereby the operator may answer the call or listen in on the line at any time to determine whether it is busy.

The intermediate office B is equipped also with jacks 46 and 47, the former of which is provided for signaling to ofiice A and the latter to oflice C. These jacks areprovided with normally closed tip and ring contacts which interrupt line L only when an operators cord is inserted therein. This cord is equipped with a master ringing key having a contact 61, which in its normal position connects a source of 60 cycle. current to the contact 63 of the key 64 and in its operated position connects a source of 135 cycles to this contact.. When, therefore, the operator inserts plug 62 into jack 46, say, and operates the key 64 she sends to station A 60,0r 135 cycles ringing current according to the position of contact 61. iThe intermediate office operator may thus call the inward or the outward operator at station A'or C, respectively, by using jack 46. or 47.

Connected acrossthe line conductors atthe intermediate. station B is a transformer 49,

the primaryof which is connected in series with an interrupter 50. Both the primary and secondary circuits-of the transformer 49 are normally held open by a relay 48, which is connected to the sleeves of jacks 46 and 47. When the operator. at the intermediate station inserts plug 62 into one of the jacks, say-46, the relayf48. isenergized by current from lll'lB'SlGVG. battery, 66 of the cord. ITherelaycloses its contacts and current from battery ,6? flows through the interrupter. This current is applied to the line conductors by the secondary 49 and flows through the-contacts of jack 4? over line L to office C, thereby indicating that the line beyond the intermediate station is in use. In case there is more than one intermediate ofiice on the line it is desirable to pass the current in the secondary of transformer 49 through a codifying device which interrupts :the tone current at regular intervals and thus breaksit up into telegraphic dots and dashes for the purpose of notifying the operators which of the intermediate offices is busy. Inits present form the device 2 5 is a revolving commutator the segments of which differ for each intermediate oiiice. Any other device maybe used for rendering the tone current characteristic of the office at which it is applied to the line.

Although in the above-described form of embodiment of the invention, there are only three ofiices associated with the line it is to be understood that a greater or a smaller number of oflices may be associated, therewith as desired. The number of positions at each ofiice selectively called from the other ofiices may likewise be changed to suit convenience, it being readily understood that for each additional position it is merely necessary to provide an additional source, differing in frequency from the other sources, withselective apparatus for applying current from this source to the line and selective signal apparatus for responding to current of this frequency, similarly as described herein. The frequencies of signaling current used herein are merely illustrative and any other suitable frequencies may be used whendesired. The inward and outward positions of the terminal oiiices need not be adjacent to. eachother, but may be located in separate buildings when conditions of the SBIViCG IIIakB this desirable.

Although only one form ofapparatus and circuits embodying this invention is shown and described herein, it is to be understood that various changes and modifications may be made therein within the scope of the following claims without, departing from the spirit and scope of thisinvention.

WVhat is claimed is: y i

1. In a signaling system, a toll line. extending between two offices and terminating at a plurality of positions at one of said oifices, means whereby an operator at the other oflice may select any one of said positions, an intermediate office on said line, and means whereby an operator at the intermediate ofiice may select any one of said positions. i

.2, In a signaling system, a toll line eX tending between two oiiices and terminating at a plurality of positions atone of said offices, an operators signal at each 1393i tlon, means whereby an operator-at the other office may selectively operate any one of said signals, an intermediate oflice on said line and means whereby an operator at said intermediate oilice may interrupt said line and make connection to the part thereof associated Withthe office having the plurality of positions.

3. In a signaling system, a toll line extending between two offices and terminatingat' a plurality of operators positions at one of said offices, an' intermediate oilice on said line and means whereby an operator at the other,end ofiice or at the intermediate ofiice may selectively call an operator at any one-of said positions.

' 4:. In asignaling system, a telephone line extendingbetween two offices and terminatingat a plurality of positions at each of said oflices, signals at each of said positions, means whereby an operator at either ofiice may selectively actuate a signal at any one of the positions at theother ofiice, an intermediate office, and means at such intermediate "office whereby an operator there may interrupt said line and send different distinctive signals both ways, v

5. In combinations telephone line having two oflices, each operators positions associated with said line, a signaling device for each position, and frequency responsive devices associated with i said lineiior selectively controlling said sig naling, devices. g

6.'Incombination, a telephone line, a transformer and an audion amplifier with its input circuit connected to receive a voltage roportional to the voltage across the line due to the signaling currents therein, a plurality of devices associated with the output circuit of said audion amplifier and selectively responsive to characteris tically different currents therein, and an operators signal device associated with each selective device,

7. In combination, a telephone line, a plurality" of operators positions associated therewith, a source of'current, means other than said source for normally signaling selectively tosaid position, normally inoper tive means associated with said source for also signaling to said position, and a device for rendering said second mentioned means operative when the operator answers the first-mentioned signaling me ans.

8. In combination, a telephone line, a ack associated therewith, a cord circuit, a signal associated with said circuit, a local source of current for actuating said signal, a normally inoperative relay for controlling said source, and means for rendering said relay operative only when said cord circuit is associated with a jack, and means to operate said relay by current comingrin over the line of a different frequency from said local source.

with a plurality oi 9. In combination, a telephone line, a source of signaling current therefor at a station on said line, asecond source of current atthe same station, means normally unresponsive to signaling current in said line for controlling said second source, a cord circuit, a jack associated with said line, and means operated when said cord circuit is associated with said jack for rendering sald first-mentioned means responsive to said signaling currents. I

10. In combination, a telephone line, frequency responsive devices associated therewith, a relay controlled byeach device, a lamp relay for each of saidrelays and controlled thereby, a signal lamp for each lamp relay and controlled thereby, a jack associated with said line, a cord circuit, a cutoff relay associated with said jack and operatedwhen said cord circuit is associated withsaid j ack,and a circuit for controlling said lamp relays by said cut-off relays.

11.". In combination, a telephone line,a plurality of signaling devices, aplurality of frequency responsive devices for selectively controlling the same, anoperators cord signal, a jack for associating said signal with said line, a source of signaling current, a relay for associating said source with said line to operate said cord signal, and a second relay operated when said cord signal is associated with said line for causing said first-mentioned signaling devices to be unresponsive to said frequency responsive devices and to cause an operation of said first relay in response to said frequency responsive devices. I

12. In combination, a telephone line,a plurality of jacks, a source of current, a cord circuit for associating said source with one of said jacks, a source of current dili'ering inicharacter from said first source, a relay for connecting one or the other oi" said sources to said line, and a circuit for controlling said relay according to the jack with which said cord is associated. a

13. In combination, a telephone line, a plurality'of jacks, a cord circuit, a first relay associated with one ofsaid jacks and operated when said cord circuit is associated with said jack, a second relay, a plurality of sources of current differin in character, a third relay governed by said firstrelay selectively to associate one of said sources with the second relay, and means for controlling said second relay to associate said source with the line.

14. In combination, a telephone line, a plurality of acks, a cord circuit, a source of current associated therewith, a second source of current differing from said first source in frequency, a relay normally associating said jacks with said line, and frequency responsive means operated when said cord is associated with a predetermined one of said jacks for causing said relay to dissociate said Jacks from said hue and causing said second source of current to be connected there- With.

15. In combination, a telephone line, a source of current, a plurality of'jacks for associating said source with said line, a plurality of sources of current differing in frequency from each other and from the first mentioned source, a first relay for a'ttimes preventing said first source from being associated With said line and connecting instead one of said other sources with said line, a circuit for governing said relay according to the jack with which said first mentioned source is associated and a second resources of currents differing'in frequency v ciated With a predetermined one of said acks, contacts controlled by said first relay dlssociating said jacks from said line when said circuit is closed and for connecting one of said second mentioned sources to said line, a fourth relay for selecting one of the second mentioned sources of current for connection with the line, a fifth relay for governing said fourth relay, and a circuit operated when said cord circuit is associated with a predetermined jack for governing JOHN F. TOOMEY. 

